Concrete pipes are employed in various civil engineering and architectural applications, such as culverts and building supports. Concrete pipes are well suited for these applications since they are relatively light and strong in compression. Generally, concrete pipes are constructed by placing a reinforcing metal frame inside a mold adapted to receive and cure concrete of a predetermined composition. The resultant concrete pipe includes an outside surface and an inside surface with the reinforcing frame therebetween. One drawback of concrete pipe construction is that the placement of the metal frame relative to the outside and inside surfaces of the pipe may be altered as a result of the forming process. More specifically, it is desirable to maintain the radial location of the metal frame with respect to the internal diameter and outer diameter of the finished concrete pipe, wherein the theoretical structural behavior of the finished product is well characterized. For example, if the metal frame is offset in the form during fabrication, the finished pipe will have significantly different material properties in various areas of the pipe, which may lead to localized buckling of the frame or cracking of the concrete.
Thus, there is a long felt need in the field of concrete pipe fabrication to ensure that the reinforcing material used therein is located in the proper predetermined location subsequent to the forming operation, thus ensuring that the finished product behaves as expected. The following disclosure describes a device for selectively deforming the reinforcing frame to provide integral spacers that are adapted to engage the molding form to thus maintain the radial location of the frame therein.